Functionality of the transcriptional terminator upstream of gluQ-rs . A) Schematic representation of the terminator with a ΔG = −14.7 Kcal/mol identified using Mfold software . Bases shaded in grey indicate the two possible AUG start codons, one located in the bulge of the terminator structure and the other located 27 nucleotides downstream. The arrows indicate the site directed mutagenesis location, with the corresponding nucleotide changes designed to disrupt the predicted structure. B) β-galactosidase activity of protein extracts obtained from the corresponding clones. The plasmid pVCPDTMut has a similar construction as pVCPDT but contains the mutated terminator indicated above. The data represent the average of three experiments, each done in triplicate, and the Student t test was used to compare means between the pVCPDT and pVCPDTMut clones. *** p values <0.05 were considered statistically significant.